European Patent Office rules on disclaimers

The European Patent Office’s Enlarged Board of Appeal (EBA) has issued its decision, G2/10, regarding whether it is allowable to add negative language into a claim, in order to disclaim the presence of a feature or features, when there had only been explicit basis in the application as filed for that feature or features optionally being present.

The EBA has ruled that:

“1a. An amendment to a claim by the introduction of a disclaimer disclaiming from it subject-matter disclosed in the application as filed infringes Article 123(2) EPC if the subject-matter remaining in the claim after the introduction of the disclaimer is not, be it explicitly or implicitly, directly and unambiguously disclosed to the skilled person using common general knowledge, in the application as filed.

1b. Determining whether or not that is the case requires a technical assessment of the overall technical circumstances of the individual case under consideration, taking into account the nature and extent of the disclosure in the application as filed, the nature and extent of the disclaimed subject-matter and its relationship with the subject-matter remaining in the claim after the amendment.”

This means that the disclosure of an optional feature in the original application does not automatically provide implicit basis for a subsequent claim to an embodiment of the invention where that feature is now required to be absent.  The decision makes it clear that each case must be individually assessed to determine whether the embodiment of the invention where the disclaimed feature is absent was directly and unambiguously disclosed to the skilled person.

The emphasis in the decision is on the fact that added subject matter is assessed with respect to the subject matter that is claimed, rather than disclaimed. Therefore the EBA’s opinion is that even if the disclaimed feature was explicitly disclosed as an optional feature, this does not inevitably mean that a claim to all embodiments apart from any embodiment using that feature was genuinely disclosed to the skilled person.

There could be situations where disclaiming various optional features could result to a claim to a very specific embodiment or combination, which could potentially lead to a new and undisclosed slant as to the nature of the invention.   Therefore there is no general rule of logic that can be applied, where it could be said that if invention A and embodiment B are both disclosed then a claim to A minus B must be allowed.

Previous guidance provided by the EBA, in case G1/03, had set out when it is permissible under European law to add a disclaimer into a claim when that disclaimer has no basis in the application as filed. For such “undisclosed disclaimers” to be allowed the disclaimer must either serve the purpose of removing excluded subject matter, i.e. subject matter that was unpatentable for non-technical reasons, or achieving novelty over prior art that is an “accidental anticipation” or that is a novelty-only citation.  G1/03 also set out the criteria that must be met for these disclaimers, including that the disclaimer must be as narrow as possible, as well as being clear in scope. The present decision G2/10 draws a distinction between the specific situations for such “undisclosed disclaimers” and all other situations where an applicant is looking to include negative language to disclaim a feature, confirming that the criteria of G1/03 only apply to the specific “undisclosed disclaimers” situations.

The EBA has therefore indicated that the test to be used in the situation where the feature to be disclaimed was only originally disclosed in positive terms, as an optional feature, should not be any different to the usual test for added matter. In other words, an assessment must be made as to whether the amended claim is in respect of subject matter that was fairly disclosed to the skilled person, or whether it amounts to new information about the invention that was not genuinely derivable from the application as filed.